This invention relates to optical devices and, more particularly, to a novel and highly-effective optical device for mixing and displaying light emanating from a plurality of contrastingly-colored sources.
In my U.S. Pat. No. 3,648,521, issued Mar. 14, 1972, for "Light Indicator", I disclose a device comprising a pair of contrastingly-colored light sources, means for varying the relative intensity of the sources, and a mixing element formed with a display surface. The light from the two sources is mixed by the mixing element and displayed on the display surface. The device has many applications, including indicating by the color of the displayed light the depth or level of an explosive fluid such as a fuel for a jet airplane or space vehicle.